As disclosed in Williams U.S. Pat. No. 4,114,327, the disclosure of which is incorporated herein by reference, a pair of elongate hangers stamped from sheet metal and a pair of separate mounting brackets are used to hang an electrical box or another electrical fixture from a suspended ceiling, between a pair of eg panel-supporting bars. Similar hangers and similar mounting brackets are available commercially from S-P Products, Inc., of Elk Grove Village, Ill., under its trade designation "EZ Bar Hanger System".
Typically, as available commercially from various suppliers, an electrical box suitable for hanging from a suspended ceiling, between a pair of ceiling panel-supporting bars, opens downwardly when installed and has four side walls, each having a pair of holes pre-formed to a receive screws. Spacings between the preformed holes of the pairs vary from one supplier to another. Spacings between such holes and the lower edges of the side walls of the box vary from one supplier to another. When a pair of elongate hangers and a pair of separate mounting brackets are used to hang such a box as discussed in the preceding paragraph, the mounting brackets are fastened to an opposed pair of the side walls of the box, via screws driven through suitable holes in the mounting brackets, into the preformed holes in the opposed pair of the side walls of the box.
After the mounting brackets are fastened as discussed in the preceding paragraph, the mounting brackets are mounted on the hangers, in a manner disclosed in Williams U.S. Pat. No. 4,114,327. Usually, the mounting brackets are mounted on the elongate hangers at a selected one of multiple possible positions, which correspond to various possible spacings between such holes and the lower edges of the side walls of the box, so that the lower edges of the side walls of the box and the lower edges of the hangers are positioned approximately at a common elevation.
This invention has resulted from efforts to eliminate separate mounting brackets, which are disfavored because such brackets add material costs and installation costs, but to continuing to enable the lower edges of the side walls and the lower edges of the hangers to be approximately positioned at a common elevation.